<!DOCTYPE html>
<html>
<head>
  <meta charset="UTF-8">
  <style>
    body {
      width: 300px;
      padding: 20px;
      font-family: Arial, sans-serif;
    }
    .container {
      display: flex;
      flex-direction: column;
      align-items: center;
      gap: 15px;
    }
    h2 {
      margin: 0;
      color: #333;
    }
    p {
      margin: 0;
      text-align: center;
      color: #666;
    }
    button {
      padding: 10px 20px;
      background-color: #FFD700;
      color: #333;
      border: none;
      border-radius: 5px;
      cursor: pointer;
      font-size: 16px;
      transition: background-color 0.3s;
    }
    button:hover {
      background-color: #FFC800;
    }
  </style>
</head>
<body>
  <div class="container">
    <h2>改变背景图片</h2>
    <p>点击下方按钮将当前页面的背景图片改为皮卡丘</p>
    <button id="changeColor">改变背景图片</button>
  </div>
  <script src="popup.js"></script>
</body>
</html> 